“Over the last five years, Tom has overseen an historic investment in Chicago’s infrastructure that has helped to build a better Chicago, and I thank him for his service to the City,” Mayor Rahm Emanuel said in a statement. “Moving forward, Barrett Murphy’s vast knowledge of and experience within the Department make him the best choice for the job as we continue to implement our 10-year Capital Improvement Program.”

Powers will be replaced by the Department of Water Management’s First Deputy Commissioner Barrett Murphy. Murphy has served in a variety of capacities within the department since 2004. He was originally hired by Mayor Richard M. Daley in 1999.

His wife, Lynn Lockwood, previously served as an aide to Mayor Daley’s wife, Maggie Daley, and was appointed by Emanuel to the Chicago Public Library board in 2012. She also served as a fundraiser for the the mayor.

Murphy’s appointment still requires approval from Chicago’s City Council, but he will begin serving as the interim commissioner on May 1.

Powers’ decision was announced as the city plans to test tap water in homes where children have suffered from lead poisoning on the South and West Sides. This comes on the heels of Flint, Michigan’s current water crisis related to lead contamination.

Roughly 80 percent of the city’s properties are linked to water mains by lead pipes.